CLASS GASTROPODA 
221 
rounded, the latter narrowly umbilicated, both marked by spiral sculpture 
like that of the spire. Aperture moderately large, ovate, posterior angle 
obtuse; outer lip thin; columella strongly curved and somewhat reflected, 
provided with a strong fold a little posterior to its insertion; parietal wall 
covered with a thin callus. Length, 7.7; diameter, 3.8 mm. (Dali and 
Bartsch.) 
Type in United States National Museum, No. 206929. Type locality, 
Santa Rosa Island, California. 
Range. Known only from type locality. 
Odostomia pesa Dali and Bartsch, 1909 
Plate 62, fig. 2 
Bulletin 68, United States National Museum, 226; PI. 29, fig. 2. 
Shell elongate-ovate, very coarse and heavy. Nuclear whorls small, 
deeply obliquely immersed in the first of the succeeding turns. Post- 
nuclear whorls rather high between the sutures, well-rounded, with nar¬ 
rowly tabulate summits, marked by somewhat retractive lines of growth 
and numerous, closely placed, wavy, spiral striations. Sutures well-marked. 
Periphery of the last whorl well-rounded, marked like the spire. Base 
slightly prolonged, well-rounded. Aperture ovate, somewhat effuse an¬ 
teriorly ; posterior angle acute; outer lip very heavy; columella strong, 
flexuose with a strong, broad fold somewhat anterior to its insertion; 
parietal wall covered by a thin callus. Length, 9.3; diameter, 4.4 mm. 
(Dali and Bartsch.) 
Type in United States National Museum, No. 157458. Type locality, 
Kodiak Island, Alaska. 
Range. Known only from type locality. 
Odostomia sanjuanensis Bartsch, 1920 
Journal of Washington Academy of Sciences, 10:571. 
Shell elongate-ovate, wax-yellow. Nuclear whorls decollated. Post- 
nuclear whorls narrowly tabulatedly shouldered, moderately rounded, 
marked by regular retractively slanting lines of growth and fine spiral 
striations, which give to the surface a cloth-like texture when subjected 
to high magnification. In addition to this sculpture, the surface of the 
shell is marked by strong incremental lines and more or less irregular 
and irregularly distributed, spiral threads, which produce a malleated 
pattern. Suture strongly marked. Periphery of the last whorl well- 
rounded. Base moderately long, well-rounded, marked like the spire. 
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